[Bumpy]

It seems to have been lost in time in favour of the 2A3.

I know, way back, supplies were poor but companies like Softek are now making them plentiful and cheap by comparison to the 2A3. Strangely they have not made a comeback and rarely get a mention when discussing output triodes.

Can anyone explain why?

[FullRangeMan]

It seems to have been lost in time in favour of the 2A3.

I know, way back, supplies were poor but companies like Softek are now making them plentiful and cheap by comparison to the 2A3. Strangely they have not made a comeback and rarely get a mention when discussing output triodes.

Can anyone explain why?

This tube not enough expensive for the North American audiophiles.
Its not famous, not fancy name, do you think 300B was named 299 it could be this famous?

There is other 6BG4 that seems to be a duplicate name:
http://www.r-type.org/exhib/aaa0146.htm
That one are even better:
It have a built-in driver Triode in parallel what saves additional wiring, solder and sockets, it even delivery the double 2A3 power.

Similar incredible market situation happens with the great sound and big GM70 tube, its one of the best sound in history, best sound than 300B and 845 but its sells only for $20 each not $500 as 845 Chinese copies and its a Russian military tube (you know what it mean).
http://www.gstube.com/catalog/?key=gm70&submit=Find

[Bumpy]

Thanks
When I was young and lived in Brighton I had Audio Innovations 2nd Audios with 6B4G valves. I have never forgotten how good they sounded.

[FullRangeMan]

Thanks
When I was young and lived in Brighton I had Audio Innovations 2nd Audios with 6B4G valves. I have never forgotten how good they sounded.

Nice, IMO this is not about the output tube but the circuit features:
= No local or global feedback.
= Point to point hard wiring, no PCBs.
= Non maggnetic resistors;

[FullRangeMan]

You could do a better amp ordering a SE amp with the praised GU50 military tube at your favorite builder with these features and others more:
= Big transformers.
= All C core transformers.
= Tube rectifiers.
= Soft start.
= Choke.
= Manual Bias for no sound interference.
= Teflon sockets.
= Robust aluminium chassis.
In case you want tube rolling you may stick with 6SN7 + EL34.

[Steel Lab]

Hello

6B4G tubes sound better than GM70 and 300B in my experiments. They are 2A3 with 6.3V filament and are only surpassed by some transmission triodes and by 45 in my opinion.
The 6B4G has that magical sound of the 2A3 at a more affordable price. Logically, I'm talking about the 6B4G NOS and the Russian 6S4S and not that crappy Sovtek 6B4G that has completely different plates and only has good bass and bad in the other frequencies.
GU50 do not have a comparable sound...

Aldovan

[FullRangeMan]

Seems a nice tube, thanks for the heads up.

[Steel Lab]

I like exotic transmission tubes like the 3C24 and 15E, which don't use graphite plates.
I have never heard a tube with a graphite plate that was superior to that of metal plates.
See these two amplifiers that I built with the transformers I produce:

https://www.youtube.com/watch?v=EV70Jovf1gI

https://www.youtube.com/watch?v=nsqhqCjAnQo

[FullRangeMan]

Thanks for posting Aldovan, I will watch tonight on the desktop.

[planet10]

One of the best amps i have ever heard (not mine);







dave

[FullRangeMan]

Great sound quality Aldovan on these videos.
Congratulations for the great Transformers.

These vintage FR drivers also delivery great mid-range.
What are they ?
https://www.youtube.com/watch?v=dwcV38_9vfA

[FullRangeMan]

Aldovan please post your transformers in this topic if possible>
https://www.audiocircle.com/index.php?topic=129713.msg1370557#msg1370557
If you could add price would be interesting.